Auto merge of rust-lang#91728 - Amanieu:stable_asm, r=joshtriplett

Stabilize asm! and global_asm!

Tracking issue: rust-lang#72016

It's been almost 2 years since the original [RFC](rust-lang/rfcs#2850) was posted and we're finally ready to stabilize this feature!

The main changes in this PR are:
- Removing `asm!` and `global_asm!` from the prelude as per the decision in rust-lang#87228.
- Stabilizing the `asm` and `global_asm` features.
- Removing the unstable book pages for `asm` and `global_asm`. The contents are moved to the [reference](rust-lang/reference#1105) and [rust by example](rust-lang/rust-by-example#1483).
  - All links to these pages have been removed to satisfy the link checker. In a later PR these will be replaced with links to the reference or rust by example.
- Removing the automatic suggestion for using `llvm_asm!` instead of `asm!` if you're still using the old syntax, since it doesn't work anymore with `asm!` no longer being in the prelude. This only affects code that predates the old LLVM-style `asm!` being renamed to `llvm_asm!`.
- Updating `stdarch` and `compiler-builtins`.
- Updating all the tests.

r? `@joshtriplett`

tests/ui/asm_syntax.rs

@@ -1,11 +1,10 @@
 // only-x86_64
 // ignore-aarch64
 
-#![feature(asm)]
-
 #[warn(clippy::inline_asm_x86_intel_syntax)]
 mod warn_intel {
     pub(super) unsafe fn use_asm() {
+        use std::arch::asm;
         asm!("");
         asm!("", options());
         asm!("", options(nostack));
@@ -17,6 +16,7 @@ mod warn_intel {
 #[warn(clippy::inline_asm_x86_att_syntax)]
 mod warn_att {
     pub(super) unsafe fn use_asm() {
+        use std::arch::asm;
         asm!("");
         asm!("", options());
         asm!("", options(nostack));

tests/ui/asm_syntax.stderr

@@ -1,5 +1,5 @@
 error: Intel x86 assembly syntax used
-  --> $DIR/asm_syntax.rs:9:9
+  --> $DIR/asm_syntax.rs:8:9
    |
 LL |         asm!("");
    |         ^^^^^^^^
@@ -8,15 +8,15 @@ LL |         asm!("");
    = help: use AT&T x86 assembly syntax
 
 error: Intel x86 assembly syntax used
-  --> $DIR/asm_syntax.rs:10:9
+  --> $DIR/asm_syntax.rs:9:9
    |
 LL |         asm!("", options());
    |         ^^^^^^^^^^^^^^^^^^^
    |
    = help: use AT&T x86 assembly syntax
 
 error: Intel x86 assembly syntax used
-  --> $DIR/asm_syntax.rs:11:9
+  --> $DIR/asm_syntax.rs:10:9
    |
 LL |         asm!("", options(nostack));
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^

tests/ui/entry.fixed

@@ -2,8 +2,8 @@
 
 #![allow(unused, clippy::needless_pass_by_value, clippy::collapsible_if)]
 #![warn(clippy::map_entry)]
-#![feature(asm)]
 
+use std::arch::asm;
 use std::collections::HashMap;
 use std::hash::Hash;
 

tests/ui/entry.rs

@@ -2,8 +2,8 @@
 
 #![allow(unused, clippy::needless_pass_by_value, clippy::collapsible_if)]
 #![warn(clippy::map_entry)]
-#![feature(asm)]
 
+use std::arch::asm;
 use std::collections::HashMap;
 use std::hash::Hash;
 

tests/ui/missing-doc.rs

@@ -2,10 +2,11 @@
 // When denying at the crate level, be sure to not get random warnings from the
 // injected intrinsics by the compiler.
 #![allow(dead_code)]
-#![feature(global_asm)]
 //! Some garbage docs for the crate here
 #![doc = "More garbage"]
 
+use std::arch::global_asm;
+
 type Typedef = String;
 pub type PubTypedef = String;
 

tests/ui/missing-doc.stderr

@@ -1,43 +1,43 @@
 error: missing documentation for a type alias
-  --> $DIR/missing-doc.rs:9:1
+  --> $DIR/missing-doc.rs:10:1
    |
 LL | type Typedef = String;
    | ^^^^^^^^^^^^^^^^^^^^^^
    |
    = note: `-D clippy::missing-docs-in-private-items` implied by `-D warnings`
 
 error: missing documentation for a type alias
-  --> $DIR/missing-doc.rs:10:1
+  --> $DIR/missing-doc.rs:11:1
    |
 LL | pub type PubTypedef = String;
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: missing documentation for a module
-  --> $DIR/missing-doc.rs:12:1
+  --> $DIR/missing-doc.rs:13:1
    |
 LL | mod module_no_dox {}
    | ^^^^^^^^^^^^^^^^^^^^
 
 error: missing documentation for a module
-  --> $DIR/missing-doc.rs:13:1
+  --> $DIR/missing-doc.rs:14:1
    |
 LL | pub mod pub_module_no_dox {}
    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: missing documentation for a function
-  --> $DIR/missing-doc.rs:17:1
+  --> $DIR/missing-doc.rs:18:1
    |
 LL | pub fn foo2() {}
    | ^^^^^^^^^^^^^^^^
 
 error: missing documentation for a function
-  --> $DIR/missing-doc.rs:18:1
+  --> $DIR/missing-doc.rs:19:1
    |
 LL | fn foo3() {}
    | ^^^^^^^^^^^^
 
 error: missing documentation for an enum
-  --> $DIR/missing-doc.rs:32:1
+  --> $DIR/missing-doc.rs:33:1
    |
 LL | / enum Baz {
 LL | |     BazA { a: isize, b: isize },
@@ -46,75 +46,75 @@ LL | | }
    | |_^
 
 error: missing documentation for a variant
-  --> $DIR/missing-doc.rs:33:5
+  --> $DIR/missing-doc.rs:34:5
    |
 LL |     BazA { a: isize, b: isize },
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: missing documentation for a struct field
-  --> $DIR/missing-doc.rs:33:12
+  --> $DIR/missing-doc.rs:34:12
    |
 LL |     BazA { a: isize, b: isize },
    |            ^^^^^^^^
 
 error: missing documentation for a struct field
-  --> $DIR/missing-doc.rs:33:22
+  --> $DIR/missing-doc.rs:34:22
    |
 LL |     BazA { a: isize, b: isize },
    |                      ^^^^^^^^
 
 error: missing documentation for a variant
-  --> $DIR/missing-doc.rs:34:5
+  --> $DIR/missing-doc.rs:35:5
    |
 LL |     BarB,
    |     ^^^^
 
 error: missing documentation for an enum
-  --> $DIR/missing-doc.rs:37:1
+  --> $DIR/missing-doc.rs:38:1
    |
 LL | / pub enum PubBaz {
 LL | |     PubBazA { a: isize },
 LL | | }
    | |_^
 
 error: missing documentation for a variant
-  --> $DIR/missing-doc.rs:38:5
+  --> $DIR/missing-doc.rs:39:5
    |
 LL |     PubBazA { a: isize },
    |     ^^^^^^^^^^^^^^^^^^^^
 
 error: missing documentation for a struct field
-  --> $DIR/missing-doc.rs:38:15
+  --> $DIR/missing-doc.rs:39:15
    |
 LL |     PubBazA { a: isize },
    |               ^^^^^^^^
 
 error: missing documentation for a constant
-  --> $DIR/missing-doc.rs:58:1
+  --> $DIR/missing-doc.rs:59:1
    |
 LL | const FOO: u32 = 0;
    | ^^^^^^^^^^^^^^^^^^^
 
 error: missing documentation for a constant
-  --> $DIR/missing-doc.rs:65:1
+  --> $DIR/missing-doc.rs:66:1
    |
 LL | pub const FOO4: u32 = 0;
    | ^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: missing documentation for a static
-  --> $DIR/missing-doc.rs:67:1
+  --> $DIR/missing-doc.rs:68:1
    |
 LL | static BAR: u32 = 0;
    | ^^^^^^^^^^^^^^^^^^^^
 
 error: missing documentation for a static
-  --> $DIR/missing-doc.rs:74:1
+  --> $DIR/missing-doc.rs:75:1
    |
 LL | pub static BAR4: u32 = 0;
    | ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: missing documentation for a module
-  --> $DIR/missing-doc.rs:76:1
+  --> $DIR/missing-doc.rs:77:1
    |
 LL | / mod internal_impl {
 LL | |     /// dox
@@ -126,31 +126,31 @@ LL | | }
    | |_^
 
 error: missing documentation for a function
-  --> $DIR/missing-doc.rs:79:5
+  --> $DIR/missing-doc.rs:80:5
    |
 LL |     pub fn undocumented1() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: missing documentation for a function
-  --> $DIR/missing-doc.rs:80:5
+  --> $DIR/missing-doc.rs:81:5
    |
 LL |     pub fn undocumented2() {}
    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: missing documentation for a function
-  --> $DIR/missing-doc.rs:81:5
+  --> $DIR/missing-doc.rs:82:5
    |
 LL |     fn undocumented3() {}
    |     ^^^^^^^^^^^^^^^^^^^^^
 
 error: missing documentation for a function
-  --> $DIR/missing-doc.rs:86:9
+  --> $DIR/missing-doc.rs:87:9
    |
 LL |         pub fn also_undocumented1() {}
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 error: missing documentation for a function
-  --> $DIR/missing-doc.rs:87:9
+  --> $DIR/missing-doc.rs:88:9
    |
 LL |         fn also_undocumented2() {}
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^^